When venturing outside to photograph the mosses, there is no way to ignore lichen. I’m not sure how lichen got to be called what its called, its not in my Encyclopedia of Word and Phrase Origins. The dictionary is not much help either, merely speculating it is of Greek origin. People often call lichen “moss” when referring to the grayish spots on tree bark. Wrong — its lichen. And it doesn’t just grow on the north side, it grows on any side that has a suitable combination of sunlight or shade, moisture and substrate. Lichen in itself is very small but can look really large when enough gets together in one area.
So, what the heck is lichen? It is actually a combination of algae and fungi. Not just any algae or fungi, but for each kind of lichen, a specific algae and a specific fungi. The algae, because they have chlorophyll, provide the proper nutrients for the fungi. The fungi in turn, help protect the algae. This partnership is called Symbiosis because they help each other, neither one hurting or destroying the other. Most people, including me, don’t need to know or even have a desire to know the actual scientific names of those algae and fungi in each kind of lichen. If however, you do, and don’t know where to find out, I’ll help. Meanwhile, we do know that because the algae are different, the form of the lichens are different. Because they are small, but cluster together, we are able to divide them into three broad categories: crustose, foliose and fruticose.
Crustose are probably the easiest to identify. They cling to rocks and wood, are flat and ususally look like some dead, dry, crusty unknown thing you discover when scrubbing the kitchen floor.
Foliose are those that appear sort of leafy, usually lie somewhat flat, but with edges that curl up away from the rock or bark or wood. They often overlap each other and can cover large areas. Pale Shield lichen and Boulder lichen are two examples of Foliose lichen.
Fruticose can also cover large areas, but are not so leaf-like, they can have branch-like structures and some can be described as bushy. British Soldiers and Reindeer moss are two examples of Fruticose lichen.
So, the next time you wander about outside, take a really close look at what is growing on those tree trunks. And on those rocks the Ozarks are famous for. See if you can find an example of all three. It is an amazing world often overlooked.